


What'd You Do That For?!

by LarryPhanGirl



Category: Supernatural
Genre: Alpha Dean, Alpha/Beta/Omega Dynamics, Bite, Comeplay, First Time, Frottage, Guilt, M/M, Mating Cycles/In Heat, Mpreg, Omega Sam, Rutting, Shame, Slow Burn, Solo Sexy Times, True Mates, bond bite, protectiveDean
Language: English
Status: Completed
Published: 2018-08-25
Updated: 2018-08-31
Packaged: 2019-05-16 07:16:24
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 6
Words: 4,309
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14806812
Author URL: https://archiveofourown.org/users/LarryPhanGirl/pseuds/LarryPhanGirl
Summary: Dean looks after his little brother, Sam who is an Omega. Sam has some trouble with some suppressants...I'm horrible at summaries.





	1. Chapter 1

What’d You Do That For?! (Wincest)

  
    “Look after your brother, Dean,” his father always said. Look after Sammy. That’s Dean’s primary job, other than hunting monsters. However, when Sam turned 16 and went into his first heat, Dean’s became Sam’s fierce protector against Alpha’s, being one himself.  After Sam’s first heat, John forced him to go on suppressants. “Omegas cant hunt monsters. You’d get killed or worse!” So Sam took the suppressants and worse the scent blockers, disguising himself as a beta. Being disguised as a beta made things easy, women didn’t expect a knot when they fucked and Alpha’s weren’t harassing him.    
  
    He ran out of suppressants and scent blockers during a long vampire hunt. Dean wanted to kill the whole nest but they had scattered. He’s been on the pills for almost 6 years so when he missed one day, his body immediately went into heat. His skin became hot, turning a light pink and sweat coating his skin. Dean was on the other bed, researching to find the other vamps. Sam curls into a ball as he feels his slick leaking out and down his leg. The scent reaches Dean’s nose and he whips his head to his little brother.    
  
    “Sammy? You okay?” Dean doesn’t move, afraid he won’t be able to restrain himself.    
  
    “Dean, leave! I n-need supplies!” a moan escapes Sam’s mouth as he grinds against the bed.    
  
    “Shit, okay, yeah,” Dean rushes out of the room, hearing Sam lock it behind him. Dean looks back at the door. _Look after your brother. Let no Alphas get him_ , Dean could hear his fathers voice. He decides that Sam needs help to get through his heat and he sure can’t help him.    
  
    Dean goes to the nearest sex shop, which is almost 45 minutes away. He starts ringing. _Sammy_. He pockets his phone and grabs random sex items that Sam could use. He pays for the items, his face deep red as the cashier gives him a knowing eye. _Shut up lady._   
  
    Finally, after almost 2 hours, he’s back at the hotel, a bag full of goodies for his baby brother. “Sammy?” Dean says, knocking on the door. “I got...the stuff,” he finishes awkwardly, not wanting to say _dildos_ out loud.    
  
    The door opens and the smell of an omega in heat knocks into Dean, almost making him fall backwards. He feels his own dick hardening but tries to squash the thought, handing the bag to Sam. “Thanks Dean. Do you mind getting a different room? I’m gonna need this one for a few days...” Sam blushes, actually blushes. Dean hasn’t seen anything so damn cute.    
  
    “Yeah, I’ll just camp out in the car,” Dean says with a smile. _That way I can watch the door in case an Alpha is dumb enough to try anything_. Sam closes the door with a nervous smile and locks it, shoving a chair under the handle. Dean goes back to the car, staring at Sam’s door.    
  
    The week goes by, no major emergencies. Dean pays for the room as Sam rushes out, his bags dangling from his arm. He gets into the car same time as Dean. “We are not talking about this. Let’s get me some suppressants, **now**.”   
  
    “Yeah, sure man. No problem!” Dean throws a smile over to his brother but it goes unnoticed by Sam who has his head in his legs, embarrassment coursing through his veins. Dean puts the car in gear and starts driving to the nearest pharmacy. He definitely does not want Sammy to go into heat again, Dean’s resolve is slowly slipping.    
  
    An hour later, Sam has 2 years worth of suppressants and scent blockers. A smile creeps onto his face as he stares at his pills and lotion. He wishes he could never have a heat again.    
  
~To Be Continued~


	2. Guilt.

**Notes for the Chapter:**

> I finally got off work for long enough to write. Let me know what y’all think.

     It’s been two years since Sam ran out of suppressants and went into heat. Sam has long forgotten it, only a fleeting memory when he pops that pill in his mouth. For Dean, however, he dreams about it every night. All he wants is to hear Sam’s moans and whimpers. He imagines himself pounding into Sam’s hole, slick dripping as Sam cries out. Two long years of Dean waking up in a sweat, cock hard as a rock and fleeting images of his naked brother.

 

    “Dean!” Sam’s voice cuts through the daydream, snapping him back to reality. “Dude, what the hell? You were totally zoned out. What’s wrong with you?” 

 

    Dean glares at his little brother. “Shut up, Sammy. Just tired, is all.” Dean throws his beer bottle in the trash and rubs his face, rubbing away his shame and guilt. 

 

    Sammy gives him the puppy dog eyes, causing Dean’s inner alpha to slowly rise to the surface.  _ My omega is so damn cute.  _ “You know, there’s no jobs right now. You can take a nap, old man,” Sammy chuckles. “Seriously. If a case pops up, I’ll let you know.” Sam settles into his bed, laptop balanced on his long legs. 

 

    Dean gets up with a groan.  _ Damn, maybe I am getting old.  _ He plops down onto the bed, tossing and turning till he finds a comfortable spot. He sneaks a glance over at Sam, his tongue slightly sticking out as he researches whatever. Dean’s breathing slowly becomes even and he starts to drift off to sleep. 

 

~~**~~

 

_ Mmm, fuck, Dean. You’re so good with your mouth.  _ Dean’s eyes pop open, the moaning of those words not coming from his own dream. He turns his head towards Sam again, who’s still focused on his computer screen, this time earbuds are in his ears. He looks lower, Sam’s hand is moving up and down. The thought hits him like a ton of bricks,  _ Sammy is masturbating to the thought of me sucking him.  _ **_Holy fuck._ ** Silently, Dean snakes a hand down his own body, wrapping two fingers around his base, trying to keep himself from cumming too soon. Sammy’s hands move lower on his body and immediately the scent of slick attacks Dean’s nostrils.  _ Omega, omega, omega, must knot this Omega.  _ He watches as Sam slides two fingers inside himself, moaning wantonly.  _ Dean, knot me. Breed me.  _

 

    Dean’s brain freezes as he hears those words, his knot forming as he growls, snapping Sam out of his orgasm induced high. “D-Dean?” Sammy sounds scared but that doesn’t register to the Alpha. Dean jumps up and on top of Sam, sniffing his scent gland, wanting nothing more than to bite down. 

 

    “Damn you, Sammy. So sexy,” Dean pants, rubbing his dick against Sam’s stomach, his knot getting bigger and bigger. Sam feels gallons of slick pour out of him, his inner Omega wanting nothing more than to shove that knot inside of him. But he keeps his hands planted next to his body, shaking slightly. Another growl makes its way out of Dean as he leans forward, lips crashing against Sam’s. “F-fuck!” One last thrust forward and Dean cums, completely covering Sam’s stomach and chest in it and even some spilling onto the bedsheets. 

 

    Sam looks up at Dean, trying to meet his eye. Guilt immediately replaces the lust and Dean throws himself off his little brother’s body. “Shit, I’m so sorry,” Dean’s voice cracks, tears threatening to spill. “Oh god, I’m so sorry!” Dean runs into the bathroom, slamming the door behind him. He looks at himself in the mirror and all he sees is a criminal. He just took advantage of his baby brother. He punches the mirror, the glass shattering and cutting up his fist but the pain barely registers. 

 

    “Dean??” Sam’s voice, panicked comes from the other side of the door. “Dean! I heard glass shatter! Are you okay??”  _ He doesn’t care, _ Dean thinks.  _ He wants you to leave. He hates you.  _ Dean throws open the door and grabs his clothes then rushes out to his Baby. 

 

    “You’re such an idiot, Dean,” he says out loud, to himself. 

 

    “God, this is gonna be awkward tomorrow,” Sam says out loud, to himself, alone in the hotel room. 

 

~~To Be Continued~~ 

**Notes for the Chapter:**

> Feel free to comment any critiques or suggestions. Or anything positive!! Also feel free to message me on kik @ emmaharrystyles or on Tumblr @ larryphan1996.


	3. Confusion

**Notes for the Chapter:**

> I think is just some filler. Tbh, I wrote this chapter late at night and it’s probably not proper grammar. But oh well, hope you enjoy!

     The morning after, Dean does not look Sam in the eyes. In fact, he downright ignores his little brother. It’s so quiet you can hear a pin drop as the brothers pack up their gear. The lady at the front desk snickers at the small hickey forming on Sam’s collarbone.  _ How the hell did that happen?  _ Dean thinks to himself. Sam gives the lady the death glare before storming out of the office. Dean gives the lady a charming smile before rushing out of the room. 

 

    Back in the car, Sam has put earbuds in, drowning out the chance for Dean to talk to him. Dean starts driving, the tension between the two growing, growing until Dean can’t take it. He growls, knocking the earbuds out of Sam’s ears. “Damn it, we have to talk Sammy!”

 

    Sammy throws Dean a glare. “No we don’t have to talk. Let’s just forget it ever happened.” 

 

    “Bro, you have a hickey!” Dean says, laughing. “When did I even do that to you? I don’t remember biting you.” 

 

     Sam sighs. “You bit me as you came...it bled a lot. How did you not notice?” 

 

    Dean shrugs. “I was preoccupied! Are you okay? Does the bite hurt?” 

 

    Sam shrugs back, chuckling. “It’s not a bond bite so it doesn’t hurt more than any flesh wound from any monster. We ran out of tape and gauze so I couldn’t cover it up.” Sam runs a finger over the hickey. 

 

     “I’m sorry, man. We can stop and get some then you cover that up.” Sam nods and looks out the window, silent again. Dean sighs, pulling the car over. “Punch me.” 

 

    “What?” Sam asks, looking at Dean like he grew two heads. “Punch you?? Why would I punch you?” 

 

    “Cause I fucked up, man. I took advantage of your vulnerable state. You’re angry, I get that. Punch me!” Dean parks the car and gets out, moving over to Sam’s side by the trees. He steels himself as Sam climbs out of the car, ready to absorb the punches. 

 

    “You’re an idiot!” Sam pushes Dean, which he wasn’t ready for, almost toppling him over. “Why would I be mad at you for something I enjoyed too?? Hell, I came as you did!” Sam pushes Dean again, this time Dean thuds against a tree and Sam moves closer. “That’s why I’m awkward. I enjoyed it, you halfwit. I dreamed about it all night last night. Now shut up and drive us back to the damn bunker.” Sam pulls away and climbs back into the Impala, slamming the door. 

 

    Dean stops and stares over at Sam for a minute.  _ What the hell?  _ He goes back to the car and looks over at his brother. “You enjoyed it?” He asks, supremely confused. 

 

    “Duh,” he looks over at the elder, rolling his eyes. “If I didn’t like it, I would’ve pushed you off. I am a tad bit stronger than you.” 

 

    “Huh,” Dean cocks his head to the side. “Well...it got more awkward.” He starts the car and makes his way back to the bunker. 

 

~~**~~ 

 

    Back at the bunker, Dean starts grilling hamburgers, hoping to ease this awkward situation with burgers and beer. Sam is at the table, doing some research, looking for a case. Dean sets a plate in front of his little brother. “Eat up, man.” Dean sits down and starts eating as well. Sam gives Dean a long look then starts digging in. 

 

    “Man, I’m a fucking genius with burgers. Always marvelous.” Dean takes another bite, moaning as he chews. 

 

    Sam chuckles. “It’s not so bad. Did a good job.” Sam grabs two beers for them both and hands one to his brother. 

 

    “Hey so, uhh...this is gonna awkward as hell but it needs to be asked. Do you have enough suppressants and scent blockers? If you do the math, your heat would be soon, if you had them,” Dean finishes, trying not to look at his brother. 

 

    “Actually,” Sam licks his lips. “I’m almost out. I got like a week worth left.”

 

    “No problem! We’ll get you some more tomorrow,” Dean grins, taking another sip of his beer. 

 

    “Speaking of awkward,” Sam clears his throat. “Why don’t you go into ruts? I’ve only ever seen you go into rut once and that was when I went into heat on accident.” 

 

    Dean laughs, throwing his head back. “I go into ruts once a month, man. I just take care of myself in my room or the bathroom,” Dean says, shrugging as he finishes talking. 

 

    “Yeah but isn’t ruts like where you need to have sex like a billion times? It can’t just be one and done!” 

 

    Dean shrugs again. “Okay so I take care of myself multiple times,” he laughs, finishes off his beer. “Sometimes bar chicks help. But they can’t take the knots. They’re all betas.” 

 

    “You’ve never been with an omega?” Sam looks at him curiously. “Like ever? I mean, does the knot appear when you’re with betas?” 

 

    “Nah, my knot doesn’t swell when I’m with betas. It only swells when I’m in ruts or,” Dean trails off, not sure how to continue. 

 

    “Or if you’re with an omega?” 

 

    “If I’m near one too. Or even just thinking of one,” Dean looks up. Sam stays silent, sipping at his beer. “Well,” Dean stands up. “I’m done with awkward conversation. Night, baby bro.” 

  
    “Night,” Sam says softly as Dean starts walking away.  _ Never been with an omega. Well, I should change that,  _ Sam thinks to himself, already starting to hatch a plan. 


	4. Giving In

     That night, Sam stays up late, going over his plan to get Dean with an omega.  _ Namely, me.  _ Once Dean was asleep in his room, Sam makes his way into the bathroom and counts his suppressants. He takes one out and crushes it between his fingers, using the sink to wash it off his skin. He knows Dean counts his pills to make sure Sam stays safe and doesn’t go into heat again. He stuffs his pills back into the cabinet and makes his way to his room again. 

 

He writes the following steps, 

 

**Step One:** Go into heat. 

**Step Two:** Rile Dean up enough he goes into rut. 

**Step Three:** Get Dean to know the hell out of me. 

 

    Satisfied with his work, he closes his laptop and closes his eyes. This plan will work. It’ll definitely work. 

 

~~**~~ 

 

    It takes almost a week for Sam to start feeling the cramps that comes before a heat.  _ Finally,  _ he thinks.  _ My plan is starting.  _ He feels his skin start to heat up, turning a light pink. Dean is sitting at the table in the middle of the bunker, knee deep in research looking for Cas. Sam’s breathing becomes shallower as he takes the steps towards his brother. 

 

    “D-Dean?” Sam whispers, hanging onto the dye of the table as he feels slick start to leak out. “Something’s wrong.” Sam tilts his head, his scent gland exploded, letting his scent drift towards his brother. 

 

    Dean eyes blow wide with lust and he cranes his head to look at his little brother. “Sam? You in heat?” Dean says, trying to keep his voice from trembling with desire.

 

    Sam notices the way Dean tenses up and he smirks to himself.  _ Step two complete. Dean’s rut is starting.  _ Sam takes another step towards Dean and as soon as he does, Dean stands up and gets ready to run. 

 

    “Dean, wait! I...I need your help. Please Dean?” Sam throws him his best puppy eyes, adding a whine at the end like when he was a kid. That always made Dean give Sam the last of the treats.  _ I want this treat.  _ Sam tilts his head as Dean looks around the room, trying to look for an escape route. “Dean, please. Don’t you wanna be with an omega?” Sam practically purrs, trying to add as much of desire to that sentence. 

 

    Dean gulps and looks at his little brother, the corner of his eyes tipping with tears. Tears that mean he can’t hold back much longer. “Sam, no,” his voice breaks and he clears his throat. The smell of Sam is almost too much to handle. “We’re brothers. It’s not normal.” 

 

    Sam lunges forward, grabbing Dean by the shirt. “We’re not normal, big brother. Never have been. So why start now?” Sam dips his head, giving Dean’s neck a big sniff. 

 

    Dean bites his lip, his limbs starting to shake a little. “Sammy,” he whispers, his hand now gripping Sam’s arm. “Sammy, this isn’t you talking. It’s the heat. It’s messing with your mind! This isn’t you. You don’t want this.” Dean starts to push Sam away, but Sam stays planted to his spot. 

 

    “Oh, shut up. I planned this, you idiot,” Sam says, pulling Dean towards the younger’s room. He pushes Dean onto the bed and climbs over him, grinding on him as hard as he can. “Please big brother? I need your knot,” Sam whispers in Dean’s ear. “I need to be knotted by you. My  _ Alpha.  _ Please!” 

 

    The fog of Dean’s mind lifts as Sam calls him his  _ Alpha.  _ A growl erupts from Dean’s throat and he grabs Sam, forcefully flipping over so Dean’s on top of Sam now. “Fuck, Sammy. Already pouring slick. Want this bad, huh? Want my knot?” 

 

    “Yes Alpha! Please!” Sam starts grabbing at Dean’s clothes, trying them rip off his body. A frustrated  _ hmph  _ escapes Sam when Dean’s clothes barely budge. Sensing his little brother’s frustration, Dean quickly undresses. Sam’s eyes rake down Dean’s body, taking in all its glory. “Need you, please,” Sam begs, pushing down his pants. 

 

   Dean helps undress Sam then grabs a condom from his duffle. “No!” Sam reached out and grabs the condom then throws it across the room. “Wanna feel you, big brother.” 

 

    Dean moves between Sam’s legs, wrapping his hand around the base of Sam’s dick, causing a whine to bubble up from Sam’s throat. Dean smirks at the whine as moves his hand slowly, going down to the copious amount of slick leaking out of his brother. “Breathe,” Dean whispers and as soon as Sam sucks in a breath, Dean slides two fingers into Sam. Sam bucks up into Dean’s hand and let’s out broken curse. Dean preps him a bit more but his own patience is wearing thin.  _ I need him now.  _

 

    Sam wraps his legs around Dean’s waist, pushing against him, trying to get him as close as he can. Dean lays a hand on Sam’s hip as he slowly pushes himself in, the slick allowing him to ease in with minimal pain. Sam closes his eyes and sighs happily as Dean is finally fully seated inside him. Dean starts to move slowly, not wanting to hurt the man below him. 

 

    “Harder, Alpha, please,” Sam whispers, thrusting his hips, wanting Dean to go faster as well. The gears click in Dean’s head,  _ My omega, mine to breed, to knot.  _ Dean pulls almost all the way out, tearing another whine from Sam, then slams back in to the hilt, tearing a loud scream from Sam. He keeps going as hard and fast as he can, the moans and dirty talk from Sam, cheering him on. “I want your pups, alpha. Please!” Dean’s mind shuts down and all he can think of is,  _ BREED.  _ His knot starts swelling and he looks Sam in the eyes, silently asking for permission. Sam gives him a small smile and Dean thrusts hard one more time, his knot slipping in and he cums, pumping Sam’s dick until his own orgasm. Just as Sam cums, he bares his neck and Dean’s eyes narrow in on it. Sam gives him a strange look as he bends his head and sinks his teeth straight into the scent gland.  **Bonded** . 

 

    It’s quiet for a while, both of them waiting for Dean’s knot to go down. Once he’s able to pull out, Sam quickly gets up and runs into the bathroom. “You bit me!” he yells from the bathroom. He comes back out, holding a paper towel to his neck. “You bonded me, you idiot!” 

 

    Dean just stares at his brother, his mind still clouded by Alpha hormones. “Shit.” 

 

~~To Be Continued~~

 

**Notes for the Chapter:**

> Hope y’all like it! I know I keep leaving off on cliffhangers and for that, I’m not sorry ;)


	5. Finally

********

     Sam rushes out of the room, every instinct of his inner Omega begging him to go back.  _ We’re bonded now,  _ Sam thinks to himself.  _ Bonded for life.  _ He lays down, covering himself up to his eyes. Secretly, he smirks to himself.  _ I bonded to the one I love and trust the most. _

    Dean, on the other hand, was having a rough time in his bedroom. He couldn’t get over the guilt of bonding with his brother.  _ Disgusting, wrong. Dad would be so disappointed.  _ Suddenly, he starts to feel something else. Happiness starts to course through him, but it feels different. Dean jumps up and runs to Sam’s room. “Sammy?” 

    Sam looks up from under his blanket. “Um, hi?” 

    “Do you feel that? It’s like I can feel someone else’s happiness. Do you feel it?” Dean sits on the edge of Sam’s bed, causing the bed to dip and moves Sam closer.

    “Dean, that’s me. You can feel my emotions,” Sam says quietly, not wanting to scare Dean with his words. “Because of the bond.”

    “Because of the bond,” Dean replies in amazement. “But I’ve read about bonds and I’ve never read about bondmates sharing feelings.” 

_ True mates,  _ Sam thinks, a blush creeping onto his cheeks. 

    “True mates? Is that really a thing!?” Dean throws himself back onto the bed. 

    “Wait how did you know what I was thinking?” Sam gives his brother the wide eyed puppy look. “I didn’t say that out loud.” 

    Dean’s eyes widen. “I just fucking read your thoughts!” Dean jumps up off the bed and paces across the room. “What the hell is happening?!” 

    Sam grabs his laptop and starts to research. “So get this,” he pulls Dean back to the bed: “it says here that soulmates, or true bond mates, can read each other’s thoughts and feelings after being bonded. Their bond is stronger than a regular bond and its impossible to break.”

    Dean huffs. “Fuck, there goes that plan.” Suddenly, Dean is filled with second-hand sadness and he looks over at Sam, tears about to fall from his eyes. “Come on, man. We’re brothers and we’re bonded. That’s all kinds of fucked up.” 

    Sam stands up, throwing his laptop onto his bed. “Listen. This article says we’re soulmates. We always count on each other through all these life threatening situations. We love each other. Who says it can’t be more than brotherly love? Maybe the universe knew we’d only have each other in life so it made us soulmates,” on the final word, Sam is so close to Dean, pressed into his side. “Let’s just try to be happy,” Sam dips his head to whisper in Dean’s ear. “My Alpha.” 

   Dean growls and kisses Sam deeply, pushing him against the wall. He pulls away long enough to say, “You smell different. Your scent changed.” 

    “Maybe it changed because we’re bonded?” 

    Dean shakes his head. “No no, it did change after the bond. But this is even more different!” Dean leans forward and gives a long sniff of Sam’s scent gland. He throws himself back, eyes wide and wild. “You’re pregnant!” 

    “Wh-what?” Sam asks, confused. “No I can’t be, we only did it once.” 

    “Yeah, but I was in rut and you were in heat. That’s when each of us is more fertile.” He looks up at Sam and chuckles at the look on Sam’s face. “I know some things too. You’re not the only genius in the family!” 

     “I’m pregnant…” a smile makes its way to Sam’s lips. “Alpha, you got me pregnant on the first try.” He bends down and kisses Dean roughly. “Such a good Alpha, giving his omega pups right away.” 

    Dean caches his breath and looks at his little brother.  _ That he bonded to. _ He grabs Sam’s shirt and pulls him even closer. “Gonna give you so many pups.” 

    “Does this mean we quit hunting?” 

    “No, we take a pause. If there’s a case close by, we take it but other than that, let the other hunters take care of it,” Dean gives the other either a dazzling smile. “We’ll do the family thing right this time.” 

    “I love you, Dean.” 

    “I love you too, Sammy.”

~~THE END~~

**Notes for the Chapter:**

> Hey, I hope this didn’t seem too rushed or whatever. I have so many ideas for new fics that I wanna get started on but I wanted to give this fic a happy ending. I’m not the greatest writer, but boy oh boy, do I love to write! ❤️


	6. Author Note

Hey everyone. So I want to address a few things. I am not redating my fics for more hits, comments and kudos. I don’t care about those. I write because it helps with my anxiety and depression. I never wanted to post my fics but a ton of my friends were like “You should definitely post these!” So I posted them for my friends, mostly. It’s an easier way for them to read them. I do appreciate everything who reads, comments and gives kudos. But I’m not purposefully redating my fics. Like once a week I come back to fics I’ve posted and edit them, to make myself a better writer and to make my fics better. Now I know my fics seem dull and dumb and slow moving. But that’s just how I write. If you don’t like it, you don’t have to read it. I do enjoy constructive criticism but if you’re just gonna bash me, when you don’t even know me, I won’t stand for that. 

 

Thia ia gonna sound cliche but I’m taking a break from writing. Might even eventually take down all my fics. You never what your words do to someone else. But that’s it for now, I hope I’ll be able to post more fics soon as soon as mental health is okay again. 

 

Mwah, 

Emma. 


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